Quoted By:
The A1/A1x Terrier. Are they unique on their own? Not really. 50 were built and 10 survived into preservation. But what is unique is that pic related was the oldest locomotive in British Railways service when it was withdrawn in 1964. It was built in 1872, meaning it was 92 years old when it was withdrawn. Even more unique is that it's preserved on the Bluebell Railway.